This invention relates to an exhaust gas recombiner for restoring hydrogen and oxygen gases in gases extracted from a condenser of a steam engine, such as a steam turbine and the like, into water by reaction of the hydrogen and oxygen gases.
With a steam engine, water vapor used for lowering back pressure is cooled by a condenser to restore it into water and the condensed water is recovered for further use. In this case, when the water vapor is mixed with air or hydrogen or oxygen gas produced by decomposition of the water vapor, the degree of a vacuum in the condenser will lower and detrimentally affect the thermal efficiency of the steam engine. As shown in FIG. 1, therefore, an air extractor 31 is connected to the condenser 30 of the steam engine to extract air, hydrogen and oxygen gases and the like from the condenser 30.
Since the steam used for a steam turbine in an atomic power station includes tritium and the like, extracted gases as they are can not be exhausted into the ambient atmosphere. Therefore, in order to reduce the volume of the extracted gases, after the gases are preheated by an exhaust gas preheater 32, hydrogen and oxygen gases are reacted with each other to produce water vapor which is then condensed in an exhaust gas condenser 34 for further use.
For such an exhaust gas recombiner 33, a unit which comprises a large tank filled with pellet catalysts each including porous alumina pellets supporting catalysts on their surfaces has been generally used. With such a hitherto used recombiner, however, in order to obtain sufficient reaction efficiency, the filled layers must be thick or bulky. Such thick filled layers exhibit various disadvantages in that pressure losses become larger, the apparatus unavoidably becomes large, and the pellet catalysts are vibrated so as to collide with each other to be pulverized with resulting deterioration of the catalysts. Thus, the construction for filling the pellet catalysts becomes complicated.